Generator shutting down

Ron & Dee · 10-19-2006, 02:00 AM

My generator keeps shutting down when I turn the AC off.

I want to leave the generator on for a few minutes after turning most of the load off, mainly the airconditioning unit, but the generator keeps shutting down as soon as I turn the AC unit off.

Any ideas?

Thanks,

Ron

Ron & Dee · 10-19-2006, 02:00 AM

My generator keeps shutting down when I turn the AC off.

I want to leave the generator on for a few minutes after turning most of the load off, mainly the airconditioning unit, but the generator keeps shutting down as soon as I turn the AC unit off.

Any ideas?

Thanks,

Ron

CC38EL · 10-19-2006, 02:33 AM

Hi, Ron. Does your genny shutdown when the microwave finishes its cook cycle? That's close to the load of the A/C. If it does, I'm speculating that when you turn off your A/C there is a no load/reduced load condition which is interpreted by your generator as an overvoltage condition.

One of your limit switches has failed or isn't sensing the dropped load in time to tell the genny to throttle back. Another thing to check would be your EMS because it also monitors load, but I doubt it would cause your genny to shut down. That is almost always something in the control module of the generator.

An authorized repair facility should be able to diagnose this problem. But unfortunately, it won't be free.

Ron & Dee · 10-19-2006, 07:26 AM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by ua40j:
Hi, Ron. Does your genny shutdown when the microwave finishes its cook cycle? That's close to the load of the A/C. If it does, I'm speculating that when you turn off your A/C there is a no load/reduced load condition which is interpreted by your generator as an overvoltage condition.

</div></BLOCKQUOTE>

I haven't tried with the microwave.

I was also thinking about voltage condition but thought there might be other reasons. I'll wait to see if anyone else has had the same problem before I take it in for service.

Thanks for your reply,

Ron

Ron & Dee · 10-21-2006, 06:58 AM

I tried the microwave thing, after turning it off the Gen continued to run.

I tried with the AC running, after turning it off the Gen continued to run.

Looks like my generator shuting down problem is going to be one of those inconsistent, doesn't happen everytime, thing.

Ron

gunny · 10-21-2006, 02:51 PM

Make/model/spec/serial number of the generator would be helpful. Mechanical governor or electronic? What fault is shutting it down? Any work or adjustments been done recently?

NeilV · 10-21-2006, 06:11 PM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by gunny:
Make/model/spec/serial number of the generator would be helpful. Mechanical governor or electronic? What fault is shutting it down? Any work or adjustments been done recently? </div></BLOCKQUOTE>

On a 2002 the OnePlace panel should be able to display the last fault code from the genny. Just have to check the Onan and Winnie Manual for the procedure.

Ron & Dee · 10-22-2006, 08:19 AM

The make is Onan HGJAB, governor is mechanical.

The last fault indicated is 14, Overfrequency Fault.

Governer unable to maintain rated frequency. I'm assuming since the governer couldn't react to the drop in load that it could possibly be dirty and gumed up. I haven't had any maintenance performed on the Genny.

Any suggestion?

Thanks,

Ron

gunny · 10-22-2006, 11:00 AM

OK, now have something to work with.

Mechanical governor and over frequency. When the air conditioner is running the governor is holding the throttle fairly close to wide open, that's a pretty large load for that machine. When you turn the air off, it immediatley takes most of the load off and the governor should close the throttle fast enough to keep the engine speed within a reasonable parameter. If not, the over frequency protection circuit kicks in and shuts it down.

I asked previously if any adjustments had been done to this machine because if someone had turned up the idle screw on the carburator, it would do exactly what yours is doing. Someone in a mistaken effort to stop a governor from hunting may have put a screwdriver on the idle adjustment and there you go. Another possibilty is a sticky or gummed up linkage but I'd look at that idle adjustment first. Not very likely that the actual governor mechanism got dirty or is in need of adjustment.

Would strongly recommend against making any adjustments to the carburator or governor unless you know exactly what you are doing and/or have the service manual with this proceedure in hand. Read and understand any proceedures before picking up any tools.

Has it always done this? Started doing this recently?

Ron & Dee · 10-22-2006, 02:18 PM

Gunny,

No one has worked on the Generator.

The problem just start recently and only happens occasionaly.

I did adjust the altitude adjustment back to it's original position since we are no longer in the mountains.

Would it hurt to spray any lubricant around the lingage?

Thanks,

Ron

gunny · 10-22-2006, 05:30 PM

Use a silicon spray that dries and won't attract/collect dirt/dust.

Ron & Dee · 10-22-2006, 11:34 PM

Thanks Gunny,

I'll try the silicone spray first and see if that clears up the problem.

Ron